The invention relates to vehicle seats and particularly to the field of vibration isolation. In road vehicles, such as trucks, as well as off-the-road vehicles, such as tractors and scrapers, it is quite conventional to isolate vertical vibrations by mounting the seat on a resilient suspension. It is also common to provide fore and aft isolation by mounting the seat bottom on tracks which can slide fore and aft with the occupant against springs. Such fore and aft isolation systems can usually be locked out when desired since under severe vibration conditions they can hit their end stops and cause the operator's feet to move rapidly relative to the pedals in the vehicle and thus reduce, rather than increase, his ability to control the vehicle. Shock absorbers or other damping devices can reduce the aforementioned problem but they also reduce the ability to isolate vibrations. Also, when the vehicle is on either an up or down slope, the weight of the operator and seat can cause the seat to slide to one end of its isolation travel path.
The above-noted deficiencies of commercially available fore and aft isolator mechanisms would seem to suggest that a system which would permit good pedal contact at all times while minimizing violent back and forth movement of the operator's torso and heart would be highly desirable.